Adipic acid (AA) is an organic compound with the formula (CH2)4(COOH)2. Adipic acid has the following structure:

Adipic acid is a white crystalline solid used primarily in the manufacture of nylon-6,6 polyamide. Thus, from an industrial perspective, adipic acid is the most commercially important dicarboxylic acid.
Dodecanedioic acid (DDDA) is a dicarboxylic acid which is primarily used in the manufacture or preparation of antiseptics, coatings, painting materials, corrosion inhibitors, surfactants, and engineering plastics.
Dodecanedioic acid (DDDA) is used in the production of high performance nylon 6,12, molding resins, as well as adhesives and powder coatings.
Conventional adipic acid process involves the conversion of cyclohexane to adipic acid using a two-step oxidation process in nitric acid. The process requires exotic metallurgy for handling hot nitric acid (titanium). In addition, the conventional process produces significant quantities of by-product succinic acid and glutaric acid which require energy intensive separation steps, particularly crystallization. Because the succinic acid crystallizes at a temperature slightly above adipic acid, and glutaric acid crystallizes at a temperature slightly below adipic acid, there is a very narrow window of concentration and temperature wherein adipic acid can be crystallized without also crystallizing the succinic and glutaric acids. Commercially, this separation requires conducting the crystallization at sub-ambient temperatures at high vacuum, in order to remove water from the crystallizer solution as the crystals are precipitating out of solution. The vacuum compression requirement is both highly capital intensive, and highly energy intensive.
In 2012, U.S. Pat. No. 8,241,879 discloses engineered microorganisms that produce six-carbon organic molecules such as adipic acid, methods for manufacturing such microorganisms and methods for using them to produce adipic acid and other six-carbon organic molecules. More particularly, U.S. Pat. No. 8,241,879 discloses a process for a biological method for preparing adipic acid using a genetically modified yeast to convert glucose, and/or a paraffin (e.g., plant or petroleum based, such as hexane or coconut oil) to adipic acid via fermentation. U.S. Pat. No. 8,778,658, discloses and improved process for preparing adipic acid by fermentation from palm oil fatty acid.
The production of adipic acid and other diacids, such as dodecanedioic acid, by fermentation provides a new route to theses valuable materials and further avoids the production or coproduction of succinic and glutaric acids which essentially eliminates the difficult separation and purification requirements of the conventional production methods which rely on expensive crystallization. The new biological fermentation methods provide an aqueous fermentation broth comprising the diacids and their corresponding monoacid and ω-hydroxyacid. Typically, the diacids are present in the fermentation broth in concentrations of about 10 weight percent.
Such advances in the production of adipic acid produce fermentation broths which require new separation and purification solutions to produce diacids such as adipic and dodecanedioic acids as purified acids from fermentation broths containing these diacids and their corresponding monoacid and ω-hydroxyacid.
Simulation of a moving sorbent bed is described in U.S. Pat. No. 2,985,589 (Broughton et al.). In accomplishing this simulation, it is necessary to connect a feed stream to a series of beds in sequence, first to bed no. 1, then to bed no. 2, and so forth for numerous beds, the number of beds often being between 12 and 24. These beds may be considered to be portions of a single large bed whose movement is simulated. Each time the feed stream destination is changed, it is also necessary to change the destinations (or origins) of at least three other streams, which may be streams entering the beds, such as the feed stream, or leaving the beds. The moving bed simulation may be imply described as dividing the bed into series of fixed beds and moving the points of introducing and withdrawing liquid streams past the series of fixed beds instead of moving the beds past the introduction and withdrawal points. A rotary valve used in the Broughton process may be described as accomplishing the simultaneous interconnection of two separate groups of conduits.
Examples of simulated moving bed processes are disclosed, for instance, in U.S. Pat. No. 6,379,554 (method of displacement chromatography); U.S. Pat. No. 5,102,553 (time variable simulated moving bed process), U.S. Pat. No. 6,093,326 (single train, sequential simulated moving bed process); and U.S. Pat. No. 6,187,204 (same), each of the contents of the entirety of which is incorporated herein by this reference.
Methods are sought to recover target diacids components, such as adipic acid and dodecanedioic acid from fermentation broths resulting from biological methods for preparing diacids from fatty acids.